The previously datamined unlimited use Dreambound Augment Rune has been added to vendors in this week's Dragonflight Patch 10.2 PTR update, with a whopping 100,000 gold price tag!
While gold values typically inflate each tier, it's interesting to note that all three of the unlimited Augment runes since their introduction in Legion have cost around 50,000 gold, with the Dragonflight version outright doubling that cost, rather than any kind of slow and gradual increase over the course of each expansion.
Perhaps it has something to do with the general lack of gold sinks in Dragonflight, which may have been a factor in the recent North American WoW Token price spiking over 400,000 gold, or the developers could have simply decided it was past due for a price increase.